Using a 9.6 Tesla Nuclear Magnetic Resonance spectrometer, the T1 values of 30 specimens of articular cartilage from the human knee will be assessed. These values will be regressed against the percent water content and histological-histochemical grade of the specimens, in order to derive an equation relating T1 to those variables. Derivation of such an equation would lay the groundwork for creating a non-invasive, objective methodology for clinical assessment of the severity of osteoarthritis and its response to exercise.